Regex Tool is a php script for testing regular expression in PHP against custom subjects. Regex Tool can help you develop your regular expressions, since it is extremely simple enviroment for testing them and seeing the results.
Some of the best features in the Regex tool include ability to highlight the found matches in the subject, in addition to being able to see all the matches in very easy to read way. Support for both PCRE and POSIX functions exist, though some features are not available on POSIX due to PHP's limitations.
Open the Regex Tool web application
The whole tool is also available for download, so that you may use it on your local host, which greatly improves the responsiveness of the tool (as the tool relies on server side execution by refreshing the page to get new results). Regex Tool v2 has minimum requirement of PHP 5.2 and it will not work on earlier versions, as it uses features that are not available on earlier versions of PHP.
The version 1 of Regex Tool is also available for download. The tool is much simpler than the newer version, but it also has some small advantages. The version one comes completely in a single file, so it's considerably easier to deploy in addition to the fact that it works also on PHP4. However, even if asked, I will not provide support for this tool, so you are on your own, if you wish to use it.